What the order code points to
The ABB ACS355-03U-31A0-4-J404 is a catalog entry in the motor drives line, with the order code itself used to confirm the BOM line, PO line, enclosure nameplate, and panel layout drawing. The listed mass is 4.54 kg, which is a one-person lift into a wall-mounted enclosure but still heavy enough to deserve a planning note on the panel layout — not a hand-held, not a chassis-mount either.
Where this class of drive gets specified
The ACS355-03U-31A0-4-J404 is an ABB Motor Drives catalog entry aimed at small to mid-frame machine builders. The J404 suffix defines the variant configuration and must stay intact across the BOM line and any substitution check.